If you watch the beginning of the tape there is a twenty minute mini movie. At the beginning of the movie Lars is eating something and watching ACDC. When the camera looks at him from the front he has black pants. but when the angle switches he has blue jeans on. When they cut back to his face the black pants appear. this is probably because of the fact that it was taped on three different days. that would also explain the switching guitars for Kirk and basses for Jason.